This invention relates to skid-resistant, ribbed floor members and method and apparatus for forming the same. The ribbed floor member is suitable for animal enclosures and the like. The method and apparatus form indentations in the wear surface of ribs of such floor members to provide added slip or skid resistance along the ribs. Ribbed floors are typically constructed from members assembled in a parallel spaced relation with the surfaces of the members having a plurality of ribs extending along their length to increase wear life and provide skid resistance transversely to the ribs. The ribs, however, provide less resistance to skid in the direction of the rib than they do transversely of the ribs. It has been observed that animals with relatively short legs, such as swine, for example, can walk or stand on such ribbed floors with relatively little skidding or sliding but animals with relatively long legs, such as cattle, for example, tend to slip or skid in the direction of the ribs. To eliminate such skidding in the direction of the rib, interruptions in the wear surface of the rib, such as, for example, depressions may be provided. Depressions may be formed by a conventional punch and die assembly where the punch has the same or smaller dimensions than the aperture in the die. When such a punch and die assembly is used to make depressions of effective depth in the ribs, severe cracking occurs along the base of the rib adjacent the depression. The cracks weaken the floor members and also provide recessed areas which are difficult to clean and, therefore, allow undesirable bacteria to collect. Conventional tools can make only relatively shallow depressions without cracking and are generally unsatisfactory because they do not provide adequate skid resistance. A floor member having crack-free skid resistance in all directions and a method and apparatus for forming the same are thus desirable.